GrpcClient

Abstract client that calls remote endpoints using the GRPC protocol.

Implements: IOpenable, IReferenceable, IConfigurable

Description

The GrpcClient class allows you to create clients that call remote endpoints using the GRPC protocol.

Configuration parameters

  • connection(s):
    • discovery_key: (optional) key to retrieve the connection from IDiscovery
    • protocol: connection protocol: http or https
    • host: host name or IP address
    • port: port number
    • uri: resource URI or connection string with all parameters in it
  • options:
    • retries: number of retries (default: 3)
    • connect_timeout: connection timeout in milliseconds (default: 10 sec)
    • timeout: invocation timeout in milliseconds (default: 10 sec)

Constructors

Creates a new instance of the grpc client.

GrpcClient(service_client: Any, client_name: str)

  • client_name: str - client’s name.
  • service_client: Any - service client class

Fields

_channel

The GRPC client channel

_channel: grpc.Channel

_connection_resolver

The connection resolver.

_connection_resolver: HttpConnectionResolver

_logger

The logger.

_logger: CompositeLogger

_counters

The performance counters.

_counters: CompositeCounters

_options

The configuration options.

_options: ConfigParams

_connection_timeout

The connection timeout in milliseconds.

_connection_timeout = 100000

_timeout

The invocation timeout in milliseconds.

_timeout = 100000

_uri

The remote service uri which is calculated on openning.

_uri: str

_tracer

The tracer.

_tracer: CompositeTracer = CompositeTracer()

Instance methods

_add_filter_params

AddFilterParams method adds filter parameters (with the same name as they defined) to the invocation parameter map.

_add_filter_params(params: Any, filter: Any): Any

  • params: Any - invocation parameters.
  • filter: Any - (optional) filter parameters
  • returns: Any - invocation parameters with added filter parameters.

_add_paging_params

AddPagingParams method adds paging parameters (skip, take, total) to the invocation parameter map.

_add_filter_params(params: Any, paging: Any): Any

  • params: Any - invocation parameters.
  • paging: Any - (optional) paging parameters
  • returns: Any - invocation parameters with added paging parameters.

_call

Calls a remote method via GRPC protocol.

_call(method: str, context: Optional[IContext], request: Any): Any

  • method: str - name of the calling method
  • context: IContext - (optional) a context to trace execution through a call chain.
  • request: Any - (optional) request object.
  • returns: Any - (optional) feature that receives the result object or error.

close

Closes the component and frees used resources.

close(context: Optional[IContext])

  • context: IContext - (optional) a context to trace execution through a call chain.

configure

Configures the component by passing its configuration parameters.

configure(config: ConfigParams)

  • config: ConfigParams - configuration parameters to be set.

_instrument

Adds instrumentation to log calls and measures call time. It returns a CounterTiming object that is used to end the time measurement.

_instrument(context: Optional[IContext], name: str): InstrumentTiming

  • context: IContext - (optional) a context to trace execution through a call chain.
  • name: str - method name.
  • returns: InstrumentTiming - InstrumentTiming object used to end the time measurement.

is_open

Checks if the component is open.

is_open(): bool

  • returns: bool - Returns True if the component is open and False otherwise.

open

Opens the component.

open(context: Optional[IContext])

  • context: IContext - (optional) a context to trace execution through a call chain.

set_references

Sets references to dependent components.

set_references(references: IReferences)

  • references: IReferences - references to locate the component dependencies.

Examples

class MyGrpcClient(GrpcClient, IMyClient):
     def __init__(self):
        super().__init__(my_data_pb2_grpc.MyDataStub, 'my_data_v1')

    ...
    def get_data(self, context, id ):
        timing = self.instrument(context, 'myclient.get_data')
        result = self._call("get_data", context, { id: id })
        timing.end_timing()
        return result
    ...

client = MyGrpcClient()
client.configure(ConfigParams.from_tuples(
    "connection.protocol", "http",
    "connection.host", "localhost",
    "connection.port", 8080
))
result = client.get_data("123", "1")